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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 kf6Ua6DBeF/GrQmOtNZFsg==

<SEC-DOCUMENT>0001140361-06-006940.txt : 20060508
<SEC-HEADER>0001140361-06-006940.hdr.sgml : 20060508
<ACCEPTANCE-DATETIME>20060508161915
ACCESSION NUMBER:		0001140361-06-006940
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060501
FILED AS OF DATE:		20060508
DATE AS OF CHANGE:		20060508

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NESTOR INC
		CENTRAL INDEX KEY:			0000720851
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				133163744
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		42 ORIENTAL STREET
		STREET 2:		THIRD FLOOR
		CITY:			PROVIDENCE
		STATE:			RI
		ZIP:			02908
		BUSINESS PHONE:		4012745658

	MAIL ADDRESS:	
		STREET 1:		42 ORIENTAL STREET
		STREET 2:		THIRD FLOOR
		CITY:			PROVIDENCE
		STATE:			RI
		ZIP:			02908

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KLOWAN TEODOR JR
		CENTRAL INDEX KEY:			0001361861

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-12965
		FILM NUMBER:		06817009

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		401-274-5658

	MAIL ADDRESS:	
		STREET 1:		C/O NESTOR, INC.
		STREET 2:		42 ORIENTAL STREET
		CITY:			PROVIDENCE
		STATE:			RI
		ZIP:			02908
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2006-05-01</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000720851</issuerCik>
        <issuerName>NESTOR INC</issuerName>
        <issuerTradingSymbol>NEST</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001361861</rptOwnerCik>
            <rptOwnerName>KLOWAN TEODOR JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NESTOR, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>42 ORIENTAL STREET</rptOwnerStreet2>
            <rptOwnerCity>PROVIDENCE</rptOwnerCity>
            <rptOwnerState>RI</rptOwnerState>
            <rptOwnerZipCode>02908</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP, CAO, Controller</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>3.40</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-05-05</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>75000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Exercisable as to 15,000 shares on May 5, 2006 (Grant Date) and as to an additional 15,000 Shares at the end of each successive one-year period following the Grant Date until the fourth anniversary of the Grant Date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Teodor Klowan, Jr.</signatureName>
        <signatureDate>2006-05-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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